Being that I work for a dealer, I get o.e.m. parts from my own company. However when I need parts for another type of truck, our management prefers that we go though our own aftermarket parts vendor we're associated with. I have encountered times when OEM parts were required for various makes of trucks, and all I have to do is request it at the parts Dept. and they have no objection, as long as I always check with my aftermarket vendor first.